Phil McKenna at NewScientist.com news service describes a nanotechnology advance that turns radiation directly into electricity, leading us to wonder if it thus simultaneously provides a use for nuclear waste. This nanotech application appears to be in the early stages of development, so aside from questions of just how efficient and how expensive it would be, one wonders how resistant this nanomaterial would be to radiation damage. From “Nanomaterial turns radiation directly into electricity“:

…US researchers say they have developed highly efficient materials that can convert the radiation, not heat, from nuclear materials and reactions into electricity.

Liviu Popa-Simil, former Los Alamos National Laboratory nuclear engineer and founder of private research and development company LAVM and Claudiu Muntele, of Alabama A&M University, US, says transforming the energy of radioactive particles into electricity is more effective.

The materials they are testing would extract up to 20 times more power from radioactive decay than thermoelectric materials, they calculate.

Tests of layered tiles of carbon nanotubes packed with gold and surrounded by lithium hydride are under way. Radioactive particles that slam into the gold push out a shower of high-energy electrons. They pass through carbon nanotubes and pass into the lithium hydride from where they move into electrodes, allowing current to flow.

from “Omnilingual”
“They all got out of the truck and stretched their legs and looked up the road to the tall building with the queer conical cap askew on its top. The four little figures that had been busy against its wall climbed into the jeep and started back slowly, the smallest of them, Sachiko Koremitsu, paying out an electric cable behind. When it pulled up beside the truck, they climbed out; Sachiko attached the free end of the cable to a nuclear-electric battery. At once, dirty gray smoke and orange dust puffed out from the wall of the building, and, a second later, the multiple explosion banged.”

He talks about more about how they work and are manufactured in “The Cosmic Computer” AKA “Junkyard Planet”

3. Power Cartridges
Power cartridges (also called nuclear-electric conversion units) were small things that seem to have replaced the battery and all small engines in the Terran Federation. They were collapsium coated metal cylinders which yielded substantial amounts of power with 100% efficiency — no waste heat worth mentioning. They got their energy — somehow — from radioactive materials (reactor waste, probably) stored in them. They lasted for years. It seems likely that contra gravity vehicles were powered by larger power cartridges.

[Quote from Junkyard Planet about how they're made...]

The power cartridge manufacturing plant “was built in the shape of a T. One side of the cross-stroke contained the cartridge-case plant, where presses formed sheet-steel cylinders, some as small as a round of pistol ammunition and some the size of ten-gallon kegs. They moved toward the center on a production line, finally reaching a matter-collapser where they were plated with collapsium. From the other side, radioactive isotopes, mostly reactor-waste, came in through evacuated and collapsium-shielded chambers, were sorted, and finally, where the cross-arm of the T joined the downstroke, packed in the collapsium cases. The production line continued at right angles down the long building in which the apparatus which converted nuclear energy to electric current was assembled and packed; at the end, the finished power cartridges came off, big ones for heavy machines and tiny ones for things like hand tools and pocket lighters and razors. There were stacks of them, in all sizes, loaded on skids and ready to move out. Except for the minute and unavoidable leakage of current, they were as good as the day they were assembled, and would be for another century.” [Junkyard Planet]